Animations

This page collects the different sub-pages on my site devoted to visualization and animations of our numerical simulations. Click on any of the pages below to browse the different animations and get additional information about the simulations. You can also check my blog, where I link other animations which are not from my own work, but I find particularly striking.

These movies show simulations of individual galaxies forming, starting at a time when the Universe was just a a few million years old (redshift of 100). They follow the region that will become a single galaxy by the present time, tracing the evolution of dark matter and gas, which eventually turns into stars. Those stars then ‘light up’ the medium around them: they alter it with both their radiation heating up and pushing on the medium, as well as supernova explosions.

Just like the movies here, these movies are from the same set of simulations of individual galaxies forming, starting at a time when the Universe was just a a few million years old (redshift of 100). They follow the region that will become a single galaxy by the present time, tracing the evolution of dark matter and gas, which eventually turns into stars. Those stars then ‘light up’ the medium around them: they alter it with both their radiation heating up and pushing on the medium, as well as supernova explosions.

Here is a video explaining the breakthroughs and new physics in our “Latte” simulations, the highest-resolution simulations of a Milky Way like galaxy that have ever been run to the present day, presented in Wetzel et al. 2016 (https://arxiv.org/abs/1602.05957)

These movies show simulations of isolated disk galaxies under the influence of “feedback” from massive, young stars. In the absence of such feedback, the gas in the galaxies would cool rapidly (in a time much shorter than a single orbital time), collapsing into dense ‘nuggets’ that run away to higher and higher densities until it eventually forms stars. In a single dynamical time, almost all of the gas would be turned into stars. …

These movies shows the gas and stars in a pair of gas-rich merging galaxies (similar to the galaxy M82), as they collide on a relatively “gentle” orbit in their major merger. Giant molecular clouds (GMCs) continuously form as gas cools, and collapses to high densities in the wake of strong shocks driven by the rapidly varying gravitational potential of the colliding systems. …

These movies show typical simulations of major galaxy mergers. In the mergers, two Milky Way-like disk galaxies with a 2:1 mass ratio are placed in an initial parabolic orbit. The disks are constructed in equilibrium, with properties corresponding to observed disk galaxies, and include stellar and gas disks, central spheroidal bulges, and black holes, within a dark matter halo. As the halos orbit, the galaxies lose angular momentum to the dark matter via dynamical friction and sink to the center. …

These movies show typical results of “zoom-in” simulations, following the gas that falls to galaxy centers in a major merger all the way down until it is accreted by a super-massive black hole. The largest-scale simulations begin with galaxy-galaxy mergers; these mergers funnel gas into the central regions of the galaxies, raising its density by a factor of ~100-1000. Because of the huge dynamic range in the problem, it is impossible to resolve the small-scale physics around the black hole at the same time as the large-scale galaxy collision. …